How much smaller will lossless compression make my PDF?

It varies enormously — anywhere from a few per cent to a third, depending on how much structural overhead the file carries. Documents that have been edited and re-saved repeatedly tend to benefit most. Cleanly generated files may barely change, and the tool will tell you when that is the case.

Is anything at all lost?

No page content. Text, images, fonts and vector graphics are all preserved exactly. Only the file's internal structure is reorganised.

When should I use a stronger level instead?

When you need a large reduction and the document is image-heavy — a scanned document, for instance, where searchable text was never there to lose. Be aware that any level above Lossless converts pages into images, which removes text selection permanently.

How small can you make my PDF?

It depends entirely on what is in it. Scanned documents and image-heavy files often drop by 70 to 90 per cent. A text-only PDF exported from a word processor is already efficient and may barely change — the tool will tell you when that is the case rather than shipping a pointless file.

Will the text still be selectable after compression?

With the Lossless level, yes — nothing about the page content changes. With Balanced, Strong or Target size, pages are re-rendered as images, so text becomes part of the picture and is no longer selectable or searchable. Choose Lossless if searchable text matters more than size.

What does the target size mode actually do?

It tries a sequence of six settings, each combining a lower render resolution with a lower image quality. As soon as one produces a file at or under your target it stops and hands that back. If none of them reach the target, you get the smallest usable version along with a note saying the target was not met.

Why did my file get no smaller?

Some PDFs are already optimised — text-only documents from Word or LaTeX typically are. In that case re-rendering would make the file larger, not smaller, so the tool keeps the better of the two results and tells you it could not improve on it.

Are the page dimensions preserved?

Yes. Even when a page is re-rendered at a lower resolution, the output page keeps the original point size, so the document still prints at the correct physical dimensions.

Lossless PDF Compression

Shrink a PDF so it fits an upload limit or an email attachment.

Drop your PDF file here

or browse your device

A single PDF file, up to 150 MB. Files are processed on this device.

Lossless compression means exactly what it says: not one pixel of your page content changes. Text stays selectable and searchable, images keep their original resolution and encoding, and vector graphics remain vector. The saving comes from how the file is organised internally, not from what it contains.

This is the right choice when the document has to stay intact. Contracts you may need to search, reports where the text must remain copyable, and anything going into a records system that expects real text rather than pictures of text.

It is also the honest choice about expectations. Lossless compression on a well-built PDF may save very little, because there was not much structural waste to remove. When that happens the tool says so rather than handing you a file that is 1 per cent smaller and calling it a success.

Almost every PDF that is too large is too large for the same reason: it contains page images at a far higher resolution than anyone will ever look at. A phone photo of a receipt dropped into a document can easily be 8 MB on its own. PDFNova's compressor attacks that directly, and it tells you honestly what it achieved.

There are four levels. Lossless rewrites the file structure without touching a single page, which helps some documents and does nothing for others. Balanced and Strong re-render pages at a lower resolution and quality. Target size keeps trying progressively harder settings until the file fits the number you gave it, which is what you want when a portal refuses anything over 1 MB.

How to compress a PDF file

Add your PDF
Drop in the file you need to shrink. Files up to 150 MB are accepted.
Pick a compression level
Start with Balanced. Choose Lossless if the document must not be re-rendered at all, or Target size if you have a hard limit to meet.
Set your target, if you have one
With Target size selected, enter the ceiling in kilobytes. 1024 KB is about 1 MB, 500 KB is a common email-friendly limit.
Compress
Progress is reported page by page. Larger documents take longer because every page is re-rendered.
Check the numbers and download
The results panel shows the original size, the new size and the saving. Preview the document before downloading to confirm it is still readable.

Why use this compress pdf tool

Text stays selectable

Page content is untouched, so text remains searchable, copyable and sharp at any zoom level.

Images keep their resolution

Embedded images are copied in their original encoding — nothing is decoded, resampled or re-compressed.

Safe for records

The document remains a faithful copy of the original, suitable for archives and systems that expect real text.

A real size target

Give the tool a number in kilobytes and it will keep trying harder settings until the output fits, rather than compressing once and leaving you to guess.

It never makes things worse

If aggressive compression produces a larger file than a simple structural rewrite, the smaller of the two is what you get. The result is never bigger than what a plain re-save would give you.

Honest reporting

You are shown the before and after size and the percentage saved. If a document was already well optimised and could not be improved, the tool says so instead of pretending.

Features

Four levelsLossless, Balanced, Strong, and an iterative Target size mode.
Size targetingSix progressively stronger passes are tried until your target is met.
Before and afterEvery run reports the original size, final size and percentage saved.
Preview firstRead the compressed document in the browser before you commit to it.
Cancel mid-runStop a long compression at any point without leaving a partial file behind.

When people use this

Meeting an upload limit

Government portals, job applications and court filing systems routinely cap uploads at 1, 2 or 5 MB. Target size mode exists for exactly this.

Emailing a scanned document

A scanned twenty-page contract can easily exceed 25 MB. Balanced compression usually brings it under a typical mail attachment limit while keeping it perfectly readable.

Publishing to a website

Smaller PDFs load faster for readers on mobile connections and cost you less bandwidth.

Archiving a folder of documents

Compressing before archiving keeps years of paperwork from filling a drive, at a quality level that is still fine to read.

What lossless compression actually removes

A PDF is a collection of numbered objects with a cross-reference table pointing at them. Documents assembled by exporters, or edited repeatedly, accumulate structural overhead: objects stored individually where they could be packed together, and cross-reference tables written in a verbose format.

Lossless compression rewrites that structure using cross-reference streams and object streams, which pack many small objects into single compressed blocks. Page content — the text, the images, the vector instructions — is copied across byte for byte and never touched.

How much this saves depends entirely on how the original was produced. Documents from certain exporters, or files that have been edited and re-saved many times, can shrink noticeably. A cleanly generated PDF may barely move, because there was nothing wasteful to reclaim.

If lossless does not save enough for your purposes, the Balanced, Strong and Target size levels are available on the same page. Those do re-render pages, which is a real trade-off — text becomes part of the image and is no longer selectable — but it is where the large savings live.

How compression works

The Lossless level loads the document with pdf-lib and re-saves it using cross-reference object streams. This packs the file's internal structure more tightly without altering any page content — useful for documents with a lot of structural bloat, neutral for everything else.

The other levels take a different route. Each page is rendered to a canvas with pdf.js at a chosen scale, encoded as a JPEG at a chosen quality, and embedded into a fresh PDF at the original page dimensions. Target size mode walks through six scale-and-quality pairs from 1.5x at 82 per cent quality down to 0.55x at 34 per cent, stopping at the first one that meets your number. Whatever route is taken, the final output is compared against the plain lossless rewrite and the smaller of the two wins.

Privacy

Your files are not uploaded. When you add a PDF file, your browser reads it from your device into the memory of the tab you are looking at, and the compress pdf operation runs there using your own processor. Nothing is transmitted to any server at any point.

That means there is no file for anyone to store, no retention policy to trust, and no deletion schedule to take on faith. The document exists only in the memory of an open browser tab, and it is released the moment you close it, reload the page, or press start over.

The site uses standard anonymous analytics to count page views and how often each tool is used. Those events record which tool ran and whether it succeeded — never a file name, never file contents, and never anything that could identify a document or the person processing it.

No account is required, so no personal information is collected. There is no profile, no history and nothing tied to an identity, because no identity was ever created.

Security

The strongest security property this tool has is structural: your file never travels anywhere, so there is no transmission to intercept and no server-side copy to breach. This is not a policy that could change — it is a consequence of where the code runs.

You can verify it in about thirty seconds. Open your browser's developer tools with F12, select the Network tab, and use the tool. You will see the page's scripts load — including the PDF libraries, which are fetched on demand the first time a tool runs — and then nothing further. No request carrying your document is ever made.

For a stronger test, disconnect from the network once the page has loaded. The tool will keep working exactly as before, which is only possible because nothing is being sent.

Uploaded files are validated in the browser before anything runs: the extension must match what the tool accepts, the file must not be empty, and it must be within the size limit. Malformed documents produce a clear error and a retry option rather than a silent failure.

What this tool does not do

Being clear about limits is more useful than a feature list that quietly omits them. Any level other than Lossless converts page text into an image, which removes text selection, copy and paste, and searchability. Compression also cannot reduce a file below the size its content fundamentally requires.

If you need capabilities beyond that — redaction, PDF/A conformance, OCR, or scripted batch processing across thousands of documents — dedicated desktop software genuinely earns its licence fee, and this is not trying to replace it. For the specific job of producing a compressed PDF, everything you need is on this page.

Frequently asked questions

How much smaller will lossless compression make my PDF?: It varies enormously — anywhere from a few per cent to a third, depending on how much structural overhead the file carries. Documents that have been edited and re-saved repeatedly tend to benefit most. Cleanly generated files may barely change, and the tool will tell you when that is the case.
Is anything at all lost?: No page content. Text, images, fonts and vector graphics are all preserved exactly. Only the file's internal structure is reorganised.
When should I use a stronger level instead?: When you need a large reduction and the document is image-heavy — a scanned document, for instance, where searchable text was never there to lose. Be aware that any level above Lossless converts pages into images, which removes text selection permanently.
How small can you make my PDF?: It depends entirely on what is in it. Scanned documents and image-heavy files often drop by 70 to 90 per cent. A text-only PDF exported from a word processor is already efficient and may barely change — the tool will tell you when that is the case rather than shipping a pointless file.
Will the text still be selectable after compression?: With the Lossless level, yes — nothing about the page content changes. With Balanced, Strong or Target size, pages are re-rendered as images, so text becomes part of the picture and is no longer selectable or searchable. Choose Lossless if searchable text matters more than size.
What does the target size mode actually do?: It tries a sequence of six settings, each combining a lower render resolution with a lower image quality. As soon as one produces a file at or under your target it stops and hands that back. If none of them reach the target, you get the smallest usable version along with a note saying the target was not met.
Why did my file get no smaller?: Some PDFs are already optimised — text-only documents from Word or LaTeX typically are. In that case re-rendering would make the file larger, not smaller, so the tool keeps the better of the two results and tells you it could not improve on it.
Are the page dimensions preserved?: Yes. Even when a page is re-rendered at a lower resolution, the output page keeps the original point size, so the document still prints at the correct physical dimensions.

Browse every PDF tool, or read the help and FAQ pages. Details of how files are handled are in the privacy policy.